I just had a hard lock-up not even a Alt+Shift+PrtSC+R+S+E+I+U+B could solve, and when rebooting, the skype window was asking me for the userid and password, which is weird, because I had entered them before.
I am wondering if skype was trying to update something that caused the lock-up, and that's why I have to enter the userid/pwd again on reboot.
Has anyone else seen this?